This application claims priority to German Utility Model Application No, 201 01 174.3, filed Jan. 23, 2001 in the German Patent Office.
The invention relates in general to a breast prosthesis. More particularly, the invention relates to a breast prosthesis comprised of at least two bodies formed to imitate the shape of a breast, the bodies being welded in at least one plastic film and formed of an addition-vulcanized two-component silicone rubber mass, and in which that portion of the prosthesis facing toward or received against the body of the user is comprised at least in part of a temperature phase change material having a phase change temperature approximately that of the user""s body temperature.
A method is known, for example, from DE 27 01 672 for the manufacture of breast prostheses from shell-shaped bodies which are formed to imitate the shape of the breast. The bodies comprising the prosthesis are welded in plastic films and are made from an addition-vulcanized two-component silicone rubber mass. The prosthetic breasts manufactured by this method are formed to imitate the shape of the natural breast in almost ideal manner in that the appearance and the behavior of the prostheses mimic a natural breast due to the elastic softness, the movability, the consistence and the weight of the material used in the prostheses.
The breast prosthesis is secured to the breast of the wearer to be as unslippable as possible thereon. For this purpose, it is known, for example from EP 392 960, to provide a breast prosthesis of the type described above, which is provided with a circumferential, lip-like border area on its rear side with a circumferential shoulder which is formed by a step and on which adhesive strips or adhesive pieces are secured which interact with the adhesive regions or strips secured to the body of the woman by a hypo-allergenic adhesive such that the prosthesis is connected to the adhesive strips adhering to the skin and can be released from these again. A hook-and-loop fastener is, for example, provided as the securing means in this connection.
Particularly when the breast prosthesis is secured in accordance with its intended purpose properly and in a manner as unslippable as possible to the breast of the wearer, the problem of an unpleasant accumulation of heat often occurs under the prosthesis. The reasons for this are the deficient ventilation and the poor heat transport of the plastic materials of the prosthesis used. In order to improve the comfort in wear, it is, for example, known from DE 44 21 516 C1 to provide a breast prosthesis with a textile rear side in which a cavity between the textile rear side and the prosthesis consisting of plastic can be filled in with cotton wool. However, this solution does not result in the desired comfort in wear, either.
The invention here comprises a breast prosthesis at least partially comprised of, at least on its side or surface facing or received against the user""s body, a phase change material (xe2x80x9cPCMxe2x80x9d). The PCM will have a phase changing temperature in the region of, i.e., approximate, a person""s body temperature. During a phase change, for example from a solid state to a liquid state or from the liquid state to a vapor phase, the PCM material is capable of absorbing a certain amount of heat at a constant temperature. This amount of heat is also termed latent heat. On the reverse phase change from a vapor to a fluid or from a fluid to a solid, the stored latent heat is emitted, again at a constant temperature. In this regard these heat storing materials are characterized in that they do not require any large temperature differences to store large amounts of heat therein, for example during the storage process as a latent heat store, unlike hot water tanks.
For this reason, this phase change material is ideally suited to absorb the heat occurring below the prosthesis during the accumulation of heat at the same temperature, or to give back this stored heat again at the same temperature when the ambient temperature falls.
It is, therefore, an object of the invention to provide an improved breast prosthesis such that the discomfort in wear is largely suppressed by avoiding the heat accumulation between the prosthesis and the skin of the wearer.
This object is solved by providing a breast prosthesis comprised of at least one body formed to imitate the shape of a breast, the body being welded in at least one plastic film and formed of an addition-vulcanized two-component silicone rubber mass, and in which that portion of the prosthesis facing toward or received against the body of the user is comprised at least in part of a phase change material having a phase change temperature approximately that of the user""s body temperature.
The entire breast prosthesis can be comprised of a largely homogeneous layer in which the PCM material is mixed in with the silicone rubber mass. Alternately, the breast prosthesis can be made as a multi-layer prosthesis, preferably a two-layer prosthesis, with the PCM material only being mixed into the layer to be placed next to the body and where the layer of the prosthesis remote from the body can comprise a conventional addition-vulcanized two-component silicone rubber. The layer of the prosthesis to be placed next to the body may comprise a silicone oil or other thixotropically set liquids, a vulcanized silicone rubber, or a silicone foam into which the PCM material is embedded in each case.
In yet anther embodiment, the PCM material may be formed as a slab which is secured on the side of the prosthesis facing the body. In this regard, an air cushion can be formed between the slab-like PCM material and the prosthesis, the air cushion being capable of resulting in a better exchange of air, on the one hand, and in improved comfort in wear, on the other hand.
The PCM material can advantageously comprise a paraffin substance with a melting range of from approximately 33xc2x0 C. to 37xc2x0 C. The so-called heat paraffins used as the PCM material are paraffins especially modified for technical heat applications. These heat paraffins have a specific melting heat or melting enthalpy which is very high for organic substances at 108 kJ/kg to 250 kJ/kg.